This invention relates to a dispensing tool assembly of the type disclosed in U.S. Pat. No. 6,257,285 which issued to the assignee of the present invention and the disclosure of which is herein incorporated by reference. Similar types of tool assemblies are disclosed in U.S. Pat. No. 5,560,407 and No. 6,776,186. Such tool assemblies or tools are commonly used for evacuating, pressure testing and filling or charging fluid receiving systems on motor vehicles, such as, for example, a power steering mechanism, a radiator and coolant system, a fuel tank system and an air conditioning system. Usually, the tool assembly is supported for vertical and horizontal movement by a suspension cable and counterweight system and includes a lower tubular portion which couples with an inlet portion of the fluid system. The tubular portion is usually sealed to the inlet portion by a resilient sealing ring compressed axially by a fluid actuated piston. A flexible air suction line and a flexible liquid supply line are connected to the top of the tool assembly along with flexible pressure control lines or tubes which actuate the sealing piston and internal valves for controlling the flow of fluid in the form of liquid or air through the tool assembly.
When a tool assembly is used on a motor vehicle production assembly line, different model vehicles may be produced on the assembly line, and the change from one vehicle to another vehicle may be made without stopping a continuous moving assembly line. When a model change is made on the assembly line, it has been found desirable to provide for quickly changing a lower portion or section of the tool assembly without unthreading screws or parts in order to accommodate the inlet portion of a fluid system on a different model vehicle instead of changing the entire tool assembly. It is also usually necessary to replace the resilient sealing ring carried by the tool assembly to form a fluid-tight seal between the tool assembly and the inlet portion of the fluid system. This replacement is required due to wear of the sealing ring and sometimes must be made frequently or several times during a day of operation of the vehicle assembly line. The replacement of the sealing ring requires significant time which interrupts the use of the tool assembly.